Capturing F1 in a modal dialog?

I have several modal dialogs with "Help" buttons.  I would like to capture the F1 key from anywhere in the dialog and have it activate a help context topic for that dialog (the one associated with the button).

I tried capturing the WM_KEYDOWN message, but that doesn't seem to work.  How do I capture the F1 key event within the modal dialog?  
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NickRepinConnect With a Mentor Commented:
Check for WM_HELP
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